Every word above is false. Gary Becker’s economics of the family has many, many flaws but assuming children happen by accident is not among them. Leisure is not “mere” in economics. It’s everything that’s not work. It’s what work is for. The point is not the production; it's the consumption. If we could do the latter without the former sustainably that would be paradise. There are none, zero, no economists who think government education is dead weight loss. Even Bryan Caplan of The Case Against Education thinks it’s at least 30% human capital building and it’s glaringly obvious after the past few weeks that the child minding function of school is enormously valuable.
In practice economists assign a value of zero to child rearing. Because simply economists hate reasoning about externalities.
It's kinda telling that economics treats trained workers as something that springs into existence unbidden. While raising children is mere 'leisure' and government funded education is dead weight loss.